The Multipartite Mitogenome of Camellia sinensis cv. Xinyang10 Reveals Frequent Reorganization and Hints at Phylogeographic History

Camellia sinensis cv. Xinyang10 is a nationally recognized elite tea cultivar selected from the Xinyang drought-resistant population, valued for its notable cold tolerance and broad adaptability. In this study, we present the first complete assembly and annotation of its mitogenome. The mitogenome features a multipartite structure, consisting of a circular chromosome (798,917 bp) and a linear chromosome (46,159 bp), harboring a total of 74 genes. We identified extensive repetitive sequences (244 simple sequence repeats and 998 long sequence repeats), 211 RNA editing sites, and 16,614 bp of chloroplast-derived DNA, indicating a highly dynamic genome. Positive selection was detected in nad1 and ccmFC. Phylogenetic analysis based on mitochondrial SNP markers placed C. sinensis Xinyang10 closest to C. sinensis var. pubilimba. Notably, a phylogeny reconstructed based on mitogenomic collinearity displayed a distinct geographical pattern, supporting the hypothesized westward-to-eastward migration route of tea plants from southwestern China. These findings provide valuable genomic resources and demonstrate the utility of the mitogenome in understanding the evolutionary history of tea plants.